Supercharger for internal combustion engines



July 28, 1931. s. A. MOSS SUPERCHARGER Foa INTERNAL coMBUsTIoN ENGINES 2Sheets-Sheet 4 4 7 4 3 a 3 w 5 -|lf z K z f z l 8 3 wl z z e 5 A I; 4,-x a Ihf.. A w

Inventor. Sanford AMoss, bv fZ/Z Hls Attorneg.

July 28, 1931. s.l A, M055 1,816,737

SUPERCHARGER FOR INTERNAL COMBUSTION ENGINES Original Filed July 27,1925 2 Shelets-Sheet 2 I lveror: Samford A.I"I o SS,

buA His Attorney.

Patented July 28, 1931 SANFORD A. MOSS, F LYNN, MASSACHUSETTS, ASSIGNORT0 GENERAL ELECTRIC COM- PAINY, A CORPORATION OF NEW YORK SUPEBCHABGEBIOR INTERNAL COHBUSTION ENGINES Application led July 27, 1825, SerialThe present invention relates to superchargers for internal combustionengines and especially to superchargers of the type comprising acentrifugal compressor driven by a turbine which is actuated by exhaustgases from the engine.

The object of my invention is to provide an improved method ofregulating a supercharger of this type and an improved construction andarrangement for carrylng out such methods.

For a consideration of what I believe to be novel and my inventionattention is directed to the accompanying description and the claimsappended thereto.

In the drawings, Fig. 1 is a side elevation of an internal combustionengine provided with a supercharger embodying my invention, thesupercharger being shown in section; F ig. 2 is an end view of thesupercharger, and Fig. 3 is a view similar to Fig. l of a modification.

Referring to the drawings, Figs. 1, 2 and 3, 1 indicates an internalcombustion englne of any suitable type. For example it may be anaeroplane or automobile may comprise any suitable numbe inders. 2indicates the intake engine, 3 the exhaust manifold,

crank shaft. 0

ounted adjacent to the engine 1n any suitable manner is a superchargercomprising a turbo-compressor driven by exhaust It comprises a turlerdischarges. Discharge scroll 16 is con nected by a conduit 17 to theintake manifold 2. Adjacent to the compressor 1s a carbure- 8 is animpeller o No. 46,252. Renewed August 11, 1980.

tor 18 connected by a conduit 19 to compressor inlet 15. Carburetor 18is indicated only diagrammatically and may be of any suitable type andmay be su plied with fuel in any suitable manner. Iltis air intake isindicated at 20. his particular arconduit 20 is a butter a choke valveand W ich may be provided with any suitable type of controlling andadjusting means. haust gases from the engine are supplied to the turbineto actuate it by a conduit 22 which leads from exhaust manifold to tn rbcharged after aving the turbine whee e exhaust gas-driven turbo-supersofar described is shown only by f example and is to be taken as typicalof any suitable supercharger structure of this type.

y present invention relates particularly e method of and the ofSupercharging may be her words, it relates to the method of and themeans for regulating the met with in practice. There is available anabundance of gases with which to operate the turbine. These gasesexhaust from the engine at substantially the pressure of the surroundingatmosphere so that to obtain from them energy for operating the turbineit is necessary to build up a l on the engine to provide the requlreddrop in pressure through the turbine to effect its operation. However,it is desirable to maintain as low a back pressure on the engine aspossible because the efficiency of the engine ordinary turbine decreaseswith increase in the back pressure. The problem is, therefore, to o ratethe superchanger to obtain the desire degree of supercharging but at thesame time to impose the least possible pressure on the engine.

I-Ieretofore, in re ulatin gas-driven turbosuperchargers, it as been thepracticeto provide an exhaust conduit for the engine dischargingdirectly to the atmosphere and also a` conduit leading to the turbine, avalve being provided in the former exhaust conduit for throttling andthereby diverting gases to the conduit leading to the turbine. With thisarrangement, when the 4throttle valve in the atmospheric conduit is wideopen, substantially all the gases escape through it directly toatmosphere, little passing through the turbine wheel. As the throttlevalve is gradually losed, the exhaust gases are. directed in larger andlarger quantities to the turbine to effect its operation at higher andhigher speeds, the back pressure on the engine being at the same timegradually increased. With this arrangement, a back pressure is imposedon the engine of a value such that the portion of the gases passingthrough the turbine will operate it at the desired speed.

Now according to my invention, I pass all the exhaust gases from theengine through the turbine all the time and I regulate the turbine byregulating the bucket area acted upon by the ases, the bucket area beingdecreased to e ect an increase in the power and the rate ofsupercharging, and the bucket area being increased to eect a decrease inthe power and the rate of supercharging. This arrangement has theadvantage that the energy of all the exhaust gases is being used all thetime so that for a given degree of supercharging, the minimum amount oback pressure is imposedon the engine. At the saine time, the turbineserves also as an efficient muiler for engines.

In carrying out my invention, I provide a total active bucket arca suchthat when all of it is supplied with exhaust gases, the area will be solarge that the drop in pressure through it will be of small value andhence but little turning movement will be imparted to the turbine Wheel.In fact under these conditions, the turbine will function primarily-as amuiller for the engine and also as a means to rotate the impeller, formixing to the air in advance of the superand will subject the engine toa minimum back pressure. I then provide means whereby the active bucketarea may be gradually decreased to a certain minimum value at whichvalue the maximum degree of supercharging will be obtained, and themaximum back pressure imposed on the engine.

My invention may be carried out in connection with a turbine of eitherthe impulse supplied charger,

or reaction type, an arrangement embodying an impulse turbine beingshown in Figs. 1 and 2, and an reaction turbine being shown in Fig. 3.

Referring now specifically to Figs. 1 and 2, 24 indicates a nozzle boxwhich may be of any suitable shape. Conduit 22 connects with it andconveys exhaust gases from the engine to it. Nozzle box 24 is providedwith nozzles 25 which cover an arc of the turbine wheel buckets andserve to direct the gases from the nozzle box to the buckets. These arenozzles suitable for an impulse turbine and designed to meet the serviceof the particular conditions present. Nozzles 25 are divided into aplurality of groups, three groups indicated at a, band c being shown inthe present instance, by valves 26 and 27. Conduit 22 communicatesdirectly with nozzle group b but conimunicates with groups a and c byway of valves 26 and 27. Valves 26 and 27 may be of any suitable typeand may be operated in any suitable manner. In the present instance theyare shown as being butterfly valves carried by stems pivoted in walls ofthe nozzle box. On the ends of the stems are pinions 28 with which meshracks 29 formed on the ends of rods 30. Rods 30 are carried in guides 3land are biased to positions wherein valves 26 and 27 are open, bysprings 32 located between the guides and collars 33 on the rods. At 34is a shaft journaled in suitable bearings (not shown) and provided withcams 35 and 36, one for each rod 30. The ends of rods 3() are held inengagement with cams 35 and 36 by the springs 32. Shaft 34 has a pinion37 at one end with which meshes a rack 38 on the end of an actuating rod39. At 40 is indicated a guide for rod 39. Connected to rack 38 is anactuatingy means 41, here shown as being in the form of a foot pedal. Inthe case of an automobile, for example, this may be the acceleratorpedal for the usual engine throttle valve. The engine throttle valve isindicated at 42. Connected to it isan operatin rod 43 which is moved bya cam 44 on shaft 34. A spring 45, arranged between a guide 46 for rod43 and a collar 47 on rod arrangement embodying a 43, serves to biasvalve 42 toward closed position and the end of rod 43 to a positionwherein it is in engagement with cam 44.

Cams 3.5, 36 and 44 are offset relatively to each other,

thc arrangement being such that the gasoline in Cases Where the gasolineis. when rod 34 is turned, cam 44 first opens the means foraccomplishing the desired function may be used. i.

en the en ine is idling, the arts are in the positions s own in Fig. 1 othe drawings, throttle valve 42 being substantially closed and valves 26and 27 being wide open. Under these conditions all the exhaust gasesfrom the engine pass through conduit 22 to nozzle box 24, and from therethrough all the groups of nozzles to the turbine Wheel and thence to theexhaust conduit 23. At this time because of the large nozzle areathrough which the exhaust gases flow, there is but little pressurethrough the nozzles. turbine wheel will paratively low speed and willproduce little if any supercharging of the engine.

he engine will operate in the usual `manner, air being drawn in throughcarburetor scroll 16 from whence it flows through conduit 17 to theengine intake manifold 2. Now, when it is desired to increase the speedand power of the engine, the pedal-41 is moved to en shaft 34 is turned,cam comes into action first andgradually opens After throttle valve 42is open or substantially open, cam 36 then comes into action togradually close valve 27. As valve 27 is closed, the total nozzle areais decreased which means that the pressure of the gases in the nozzlebox will be gradually increased due to the fact that a greater pressurewill be required in order that they may How through the nozzle andbucket wheel to atmosphere. As a result more energy will be imparted bythem to the turbine wheel, the speed of the turbine wheel will increase,and supercharging will begin to take place. The amount of superchargingwill increase as valve 27 is gradually closed. After valve 27 is fullyclosed, cam comes into action to gradually close valve 26 thereby stillfurther gine. At the same time, the arrangement results in a compactstructure of simple design.

Referring now to Fig. 3, the turbine buckets 13 are shown as extendingaxially from the wheel 12 and as being of the reaction type. Conduit 22which conveys the exhaust gases from the engine to the turbinecommunicates be rotated only at a coml with the turbine casin at itscentral portion and inside the ring o buckets 13 the gases through thebuckets radially outward turbine casing and thence through the toatmosphere. Attached to the turbine casing is a valve housing in whichis located an annular valve 51 which slides on suitable rollers 52.Annular valve 51 is adapted to move relatively to bucket ring 13 so asto diminish the area of the bucket ring available for the flow of gases.Connected to annular valve 51 .is a rod 53 which rod 53. At 57 shaftcorresponding to shaft carried by it through a, rod 60 corresponding torod 43 of Fig. 1, operates the engine throttle valve 61. A spring 62serves to bias rod 60 to a position wherein throttle valve 61 is inclosed or idling position and to hold the rod 60 in engagement with cam59. Shaft 57 is provided with that provided 34 in Fig. 1, pinion 63 onthe end of the shaft being in mesh with rack 64 which is connected to apedal 65. Cams 58 and 59 are arranged relatively to each other so thatcam 59 first opens throttle valve fter which cam 58 moves valve 51 todecrease the area of bucket ring 13 available for the passage of exhaustgases.

In Fig. 3 the parts are shown in idling position. When pedal 65 is movedto increase speed of the engine, cam 59 rst gradually opens throttlevalve 61. During this time all the exhaust gases from the engine passthrough the buckets 13 of the turine wheel but owing to the large areaavailable for their passage there is but a small drop inpressure throughthe buckets, srlnall amount, if any, of supercharging takes p ace.

As the pedal 65 is moved further, valve 51 will be moved gradually overthe bucket ring 13 to decrease the area available for the passage of thegases. As this occurs, the drop in pressure through the bucket ring willgradually increase and hence the energy imparted he arrangement is suchthat valve 51 will have a total movement such that when in its innermostposition, the desired maximum amount of supercharging will be obtained.

y invention, while it may be used with advantage in connection withconstant speed engines, possesses particular utility when used inconnection with variable speed engines such as automobile engines andaeroplane enan operating means similar to'

